Voice quality analysis technique

ABSTRACT

One or more methods and systems of analyzing, assessing, and reporting voice quality scores are presented. In one embodiment, voice quality scores are generated by querying one or more computing devices responsible for processing a reference speech sample input into a voice communication system. In one embodiment, voice quality scores are transmitted by a voice analysis platform and subsequently analyzed. In one embodiment, a single voice analysis platform is used to measure voice quality of a voice communication system. In one embodiment, multiple voice analysis platforms are used to measure voice quality at multiple endpoints of one or more voice communication systems. In one embodiment, the method comprises a user determining one or more points along a communication system where transmitted reference speech samples are to be tapped. The tapped reference speech samples are ported to a voice analysis platform where a voice quality score is generated and graphically displayed.

BACKGROUND OF THE INVENTION

Traditional circuit-switched networks have been designed and optimizedfor the time-sensitive delivery of voice traffic. As a result, thePublic Switched Telephone Network (PSTN) has provided highly predictablequality of service for voice and has become the standard infrastructurefor voice transmission. The PSTN delivers toll quality speech primarilyby allocating dedicated bandwidth while using non-compressionanalog-to-digital encoding techniques. Likewise, transmission ofpredictable voice speech quality has been an important concern for voicethat travels through a packet based infrastructure, such as theInternet, because such networks may alter the time sensitive qualitiesof speech. Recently, the deployment of data networks that facilitate thetransmission of voice over Internet Protocol (VoIP), voice overasynchronous transfer mode (ATM), voice over frame relay, wireless, andtraditional wireline has created a need to assess the quality of speechbeing transmitted. When VoIP technology is deployed for voice serviceson an enterprise or commercial network, users expect a service qualitythat is tantamount to that of the Public Switched Telephone Network(PSTN).

One of the key drivers behind VoIP network deployments is lower capitalcosts of implementing voice transmission compared with traditionalcircuit-switched network deployments. However, it is important that theappropriate IP network architectures and configurations, and VoIPsystems, be implemented to deliver appropriate levels of voice servicequality. This means that up-front design and purchasing decisions willbe critical in the success and payoff of a VoIP strategy. Such decisionsbegin with assessing the IP network for VoIP performance, prior to VoIPdeployment. If the performance of an element in the VoIP communicationsystem degrades the quality of voice significantly, the resulting speechtransmitted will be unintelligible. Assessing the voice quality of aVoIP network has not been a simple task.

Voice, being a real-time media, requires quality of service tools thataddress factors that may affect voice clarity in a VoIP network.Unfortunately, a pre-deployment network assessment may be extremelydifficult to obtain. Further, a disadvantage of deploying a VoIP networkis the inability to easily and objectively measure the degradation ofvoice service quality contributed by one or more network elements withina voice transmission network (such as a VoIP network).

There are many factors that influence quality of service of a voicetransmission. Of these factors, voice quality may be the most meaningfulfrom the end user's perspective since end users decide whatcommunication services they will pay for and from whom they will buythem. It is from the perspective of the end user that voice qualityscores are best defined.

Traditional methods measure voice quality by way of subjective and/orobjective voice quality analysis between two endpoints of a voicecommunication system. One or more algorithms may be applied to the voicereceived to generate a voice quality score. However, obtaining thesevoice quality scores at various points along a network is a difficult ifnot impossible task. Furthermore, the inability to effectively providethis information to a user, such as a network engineer, provides aninefficient and costly approach to designing and troubleshooting a voicecommunication system.

Further limitations and disadvantages of conventional and traditionalapproaches will become apparent to one of skill in the art, throughcomparison of such systems with some aspects of the present invention asset forth in the remainder of the present application with reference tothe drawings.

BRIEF SUMMARY OF THE INVENTION

Aspects of the invention provide for a method and apparatus to assessvoice quality of a communication system by inputting reference speechsamples into a communication system and capturing the reference speechsample at one or more points along the communication system. Thecaptured speech sample is analyzed by a voice analysis platform thatutilizes one or more voice quality algorithms to generate one or morevoice quality scores. The reference speech sample may comprise arecording of an utterance of particular duration suitable for use by thevoice analysis platform. The recording may be sampled and stored in adata file for use by the voice analysis platform. The voice analysisplatform may generate statistics related to the voice quality scores.

In one embodiment, the apparatus comprises a voice analysis platform forgenerating a voice quality score of a communication system comprising atleast one reference speech sample generation software, at least onecommunication software, at least one voice quality scoring software, atleast one network interface, and at least one reference speech sampleinterface. The reference speech sample generation software generates areference speech sample for transmission into said communication system.The communication software provides configuration data to instruct atleast one signal processing device to provide at least one output of thereference speech sample. The voice quality scoring software generates atleast one voice quality score of the at least one output of thereference speech sample. The network interface(s) are used forcommunicating with the at least one signal processing device while thereference speech sample interface(s) are used for communicating with thecommunication system.

In one embodiment, the apparatus comprises at least a first voiceanalysis platform and at least a second voice analysis platform. Thefirst voice analysis platform is capable of generating and transmittinga reference speech sample while the second voice analysis platform iscapable of receiving the reference speech sample. The second voiceanalysis platform analyzes the received speech sample and generates avoice quality score. In one embodiment, the first voice analysisplatform or the second voice analysis platform analyzes at least oneoutput of said reference speech sample provided at a signal processingpoint within a signal processing device of said communication system.

In one embodiment, the method comprises a user determining a point alongthe voice communication system in which a reference speech sample willbe tapped. In one embodiment, the method of assessing voice quality in acommunication system comprises transmitting reference speech samples,receiving the reference speech samples captured at one or more outputsof a signal processing element of a gateway within the communicationsystem, and determining voice quality scores of the captured referencespeech samples. In one embodiment, voice quality scores and statisticalinformation may be graphically displayed to the user.

These and other advantages, aspects, and novel features of the presentinvention, as well as details of illustrated embodiments, thereof, willbe more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a block diagram of a voice test communication systemutilizing first and second voice analysis platforms in accordance withan embodiment of the invention.

FIG. 1 b is a block diagram of a voice test communication systemutilizing a voice analysis platform in accordance with an embodiment ofthe invention.

FIG. 2 is a block diagram illustrating a voice analysis platform inaccordance with an embodiment of the invention.

FIG. 3 is a block diagram of an exemplary voice test communicationsystem illustrating a transmission path taken by a reference speechsample in accordance with an embodiment of the invention.

FIG. 4 a is an operational flow diagram illustrating an exemplary methodof assessing voice quality of service in accordance with an embodimentof the invention.

FIG. 4 b is an operational flow diagram illustrating an exemplary methodof assessing voice quality of service in accordance with an embodimentof the invention.

FIG. 5 is an exemplary display provided to a user of a voice analysisplatform illustrating exemplary voice quality scores in accordance withan embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the present invention may be found in a system and method toassess voice quality of a communication system by inputting one or morestreaming reference speech samples into the communication system. Theone or more input reference speech samples may be tapped along differentprocessing points within the communication system and analyzed for voicequality by a voice analysis platform. Voice quality scores are generatedby the voice analysis platform by applying one or more algorithms to thecaptured one or more input reference speech sample. The reference speechsample may comprise a recording of speech or an utterance having aduration suitable for use by the voice analysis platform. The recordingmay be digitally sampled and stored in a data file for use by the voiceanalysis platform.

The voice analysis platform provides streaming voice data in the form ofone or more reference speech samples that are injected and captured atvarious points within a communication system. The capture pointscomprise outputs of one or more processing elements of the communicationsystem. The reference speech samples may comprise pre-recordedutterances that may be stored in a storage media of the voice analysisplatform. It is contemplated that, in one embodiment, the utterances maybe generated in one or more different languages. The voice analysisplatform utilizes one or more algorithms to generate a voice qualityscore from the captured voice data. By way of a display, the voiceanalysis platform provides a graphical diagram of the communicationsystem tested as well as one or more voice quality scores associatedwith outputs of one or more processing elements of the communicationsystem. The voice quality scores may be graphically associated with theone or more processing elements. In addition, it is contemplated thatthe display provides a graphical user interface in which to configurethe voice analysis platform. An exemplary monitor may display one ormore voice quality scores corresponding to one or more points within thecommunication system. By assessing the voice quality score at the one ormore points within the communication system, the user is able toevaluate the performance after processing is performed by one or moreprocessing elements of the communication system and subsequently isolateone or more network elements that may be responsible for causing adegradation in voice quality.

FIG. 1 a is a block diagram of a test configuration of a communicationsystem 100 in accordance with an embodiment of the invention. The testconfiguration comprises a first voice analysis platform (VAP) 104transmitting one or more reference speech samples into the communicationsystem 100. The first voice analysis platform 104 may transmit one ormore reference speech samples to an exemplary first public switchedtelephone network (PSTN) subnetwork 108, and an exemplary first voiceover IP gateway 112. The first voice over IP gateway outputs thereference speech sample to a public/private network 116 that provides amedia in which the reference speech samples are transported from thefirst voice analysis platform 104 to a second voice analysis platform128. The public/private network 116 may comprise a public/private widearea network or local area network. The network may comprise a circuitswitched or packet switched network. On the receive side, thecommunication system 100 under test comprises an exemplary second voiceover IP gateway 120, and an exemplary second PSTN subnetwork 124. Thesecond voice analysis platform 128 is used to receive the transmittedone or more reference speech samples from the public/private network 116and perform one or more types of analyses. In one embodiment, the PSTNsubnetworks 108, 124 are optional, and the voice analysis platforms 104,128 interface directly to the voice over IP gateways 112, 120.

The voice analysis platforms 104, 128 may comprise a combination ofhardware and software. The locations of each voice analysis platform104, 128 may correspond, for example, to the locations of the endpointsof the communication system under test. The hardware may comprise one ormore computing devices. The computing device may comprise a computer orthe like. The software may comprise a server or client version of voiceanalysis platform software loaded and executed within each of thecomputing devices. For example, the first VAP 104 may comprise a serverversion of voice analysis platform software installed in its computingdevice while the second VAP 128 may comprise a client version of voiceanalysis platform software installed in its respective computing device.It is contemplated that in other embodiments, multiple voice analysisplatforms may be implemented over a multiplicity of endpoints, one ofwhich may comprise a computing device utilizing a server version of thevoice analysis platform software. The other endpoints may comprisecomputing devices utilizing client versions of the voice analysisplatform software. The voice analysis platforms 104, 128 may communicatebetween each other by way of a suitable communication protocol such asan Ethernet protocol over a local area network (LAN) or wide areanetwork (WAN). One of the voice analysis platforms 104, 128 may beconfigured to act as a server (running the server version of voiceanalysis platform) while the other may be configured to act as a client(running the client version). The server may properly configure theclient prior to initiating a test. Any configuration changes may beprovided to the client in preparation for transmitting a particularreference speech sample. Such configuration changes may include thepoint at which the reference speech sample is to be tapped within agateway. The configuration information may prompt a gateway to outputthe reference speech sample at a particular processing point to one ormore voice analysis platforms 104, 128.

Analyses provided by the voice analysis platforms 104, 128 includegenerating a voice quality score. The voice quality score may bedisplayed over time in a graphical format. It is contemplated that thevoice quality score may be graphically portrayed in relation to thevoice quality score of the reference speech sample waveform. Inaddition, other statistical information, such as an average voicequality score over time and variance of calculated scores may bedisplayed. It is contemplated that the scores may be displayed accordingto the type of reference speech sample transmitted through thecommunication system and the algorithm employed.

One or more remote versions of the voice analysis platform software maybe installed in the transmit or receive side voice over IP gateways 112,120 to facilitate configuration changes to the gateways 112, 120 by thevoice analysis platforms 104, 128. The voice over IP gateways 112, 120function as signal processing devices, implementing one or more signalprocessing elements, configured to process a reference speech sample foreffective transmission through the communication system. A server, byway of its software, may control one or more clients or one or morevoice over IP gateways 112, 120. The voice over IP gateways 112, 120 mayeach comprise a computing device such as a computer. The server versionof software may be configured to provide administrative access to makingconfiguration changes and to provide control of one or more remoteand/or client versions of software. For example, the server software maybe able to facilitate generation of one or more signal processingoutputs provided by the voice over IP gateways 112, 120 by communicatingto the remote version of voice analysis platform software running in thevoice over IP gateways 112, 120. Each of the voice over IP gateways 112,120 may output the reference speech sample at particular signalprocessing points within each gateway. In this fashion, one or moresignal processing operations performed at each voice over IP gateway maybe monitored. These outputs may be received by the voice analysisplatforms 104, 128 by way of suitable network interfaces. The networkinterfaces may communicate to the voice analysis platforms 104, 128 byway of a packet switched wide area network and/or a local area network.The reference speech sample outputs may be incorporated into one or morepacket switching protocols as a method of transmitting the referencespeech sample to the voice analysis platforms 104, 128. Exemplary RTPand RTCP protocols may be used to transmit the reference speech throughan exemplary packet switched network. Furthermore, the voice analysisplatforms 104, 128 may be optionally used to test a PSTN based networkthat does not incorporate any voice over IP gateways. The embodimentillustrated in FIG. 1 a allows voice quality scores to be generated whenthe communication system connects two distinct locations. A voicequality test of the communication system may be performedbi-directionally. In this embodiment, a voice quality score of theentire communication system may be determined by transmitting thereference speech sample from the first VAP 104 to the second VAP 128.Similarly a voice quality score may be determined by transmitting thereference speech sample from the second VAP 128 to the first VAP 104.

FIG. 1 b is a block diagram of a modified test configuration of the samecommunication system 100 in accordance with an embodiment of theinvention. In this embodiment, a single voice analysis platform 150 isused to assess voice quality of the communication system 100 under test.This particular test configuration may be used in an exemplarylaboratory test setup and may be used to assess voice qualitycharacteristics of the voice over IP gateways 112, 120, other signalprocessing elements, or like devices. The voice analysis platform 150transmits a reference speech sample through the voice communicationsystem 100 and back to itself. As illustrated, reference speech samplesmay be transmitted bi-directionally and associated voice quality scoresmay be determined. Similar to that shown in FIG. 1 a, FIG. 1 billustrates the voice analysis platform 150 communicating to the voiceover IP gateways 112, 120 by way of optional exemplary first PSTN andsecond PSTN subnetworks 108, 124. The voice analysis platform 150 maycomprise a computing device running a voice analysis platform software.The voice analysis platform software may comprise a server version ofvoice analysis platform software.

FIG. 2 is a block diagram illustrating a voice analysis platform 200 inaccordance with an embodiment of the invention. The voice analysisplatform 200 may comprise any type of computing device capable ofgenerating a voice quality score by transmitting, receiving, andanalyzing a reference speech sample. As shown, the voice analysisplatform 200 comprises a communication software module 202, a speechsample generation software module 204, a voice quality scoring softwaremodule 208, a display 212, a reference speech sample interface 216, anetwork interface 220, a processor 224, a user interface 228, and amemory 232. The communication software module 202 facilitatescommunication between one or more voice analysis platforms 200 and oneor more gateways that utilize and run the communication software module202. The communication software module 202 comprises communicationsoftware that provides configuration data from the voice analysisplatform 200 to a signal processing device such as a gateway. Thegateway may comprise a voice over IP gateway. The signal processingdevice may be any device within the communication system capable ofoutputting the reference speech sample at a particular processing point.The configuration data by way of input provided by a user, may instructthe gateway to transmit an output of the reference speech sample at aparticular signal processing point within the gateway. The user mayinput one or more parameters, by way of the user interface 228,specifying which outputs from which gateway the reference speech samplewill be obtained from. The outputs are transmitted to a specified voiceanalysis platform where a voice quality analysis is performed and voicequality scores are generated. The speech sample generation softwaremodule 204 comprises speech sample generation software capable ofgenerating one or more reference speech sample files (a particular filemay comprise a sampled recording of an utterance of particular duration)to be transmitted through a communication system such as the onepreviously described in reference to FIG. 1. The speech files may bephrases or sentences spoken in one or more languages by one or morespeakers, either male or female. In one example, the reference speechsample files may be phonetically balanced utterances suitable fortesting the voice communication system. The speech files may be phraseschosen from one of several different languages. The voice qualityscoring software module 208 comprises voice quality scoring softwarethat may generate one or more voice quality scores of the transmittedreference speech sample at various points along the voice communicationsystem. The voice quality scoring software module 208 generates a scoreby comparing the reference speech sample obtained at a particular pointin the voice communication system with the reference speech samplesignal that was input into the voice communication system. For example,the voice quality scoring software module 208 may employ one or moredifferent algorithms that generate corresponding scores. For example, analgorithm, such as PESQ (perceptual evaluation of speech quality) maygenerate scores between the values of −0.5 and 4.5. Using thisalgorithm, a score of 4.5 may represent speech of highest quality orintelligibility, while a score of −0.5 may represent speech of very poorquality or intelligibility. Of course, other algorithms may employdifferent scoring scales. Other exemplary algorithms include PSQM(perceptual speech quality measurement), PAMS (perceptual analysismeasurement system), or the like. One or more of these algorithms may beapplied to the reference speech sample and graphically displayed.

The display 212 may comprise any type of system configured to displayinformation (such as a graphical user interface) to a user. The display212 may comprise a monitor or like device. The voice analysis platform200 may provide a reference speech sample interface 216 capable oftransmitting or receiving a reference speech sample to and from acommunication system under test. The reference speech sample interface216 may interface with an exemplary public switched telephone network(PSTN). The reference speech sample interface 216, for example, maycomprise FXO/FXS, E&M, E1, T1, or like type of interfaces. The voiceanalysis platform 200 may also provide a network interface 220 capableof communicating with one or more signal processing elements of one ormore gateways. In response to a request generated by configuration dataprovided by the communication software module 202 of the voice analysisplatform 200, the network interface 220 may receive outputs generated byone or more signal processing elements of one or more gateways. Thenetwork interface 220 may facilitate the transport of one or morecommunication protocols. The processor 224 provides computationalfunctions for the voice analysis platform 200. The processor 224connects to and communicates with the speech sample generation softwaremodule 204, the voice quality scoring software module 208, the display212, the reference speech sample interface 216, the network interface220, the processor 224, the user interface 228, and the memory 232.Inputs into the voice analysis platform may be facilitated by the userinterface 228 which may comprise a graphical user interface and an inputdevice such as a keyboard and/or mouse. The memory 232 provides storagefor data processing by the processor 224 during execution of software ineither the speech sample generation software module 204 or the voicequality scoring software module 208.

FIG. 3 is a block diagram of an exemplary voice test communicationsystem illustrating a transmission path taken by streaming voice data inaccordance with an embodiment of the invention. FIG. 3 depicts one ormore exemplary processing elements used in transmitting the referencespeech sample from a first voice analysis platform 304 to a second voiceanalysis platform 368. It is contemplated that the types and number ofthese exemplary processing elements may differ depending on theexemplary voice test communication system. In one embodiment, theprocessing elements may be implemented by way of a computing device suchas a voice over IP gateway. In this embodiment, the voice analysisplatform 304 transmits one or more reference speech samples to a firstpublic services telephone network (PSTN) 308. The reference speechsample may be affected by an exemplary background noise that is added tothe reference speech sample. The added background noise may degradevoice quality of the reference speech sample. In addition, the referencespeech sample may be introduced to line echo caused by a hybridjunction. The line echo may have a significant effect on speech qualityif not adequately removed by an echo canceller. Although not indicated,it is contemplated that other forms of voice quality degradation mayoccur at the first PSTN 308. Such voice quality degradation may occur byway of signal loss, cross talk, and the like.

The reference speech sample is further transmitted to an exemplary firstecho canceller (ECAN) 312 from the first PSTN 308. The first echocanceller 312 may be implemented within an exemplary voice over IPgateway as was described earlier in FIG. 1. In general, the first echocanceller 312 may cancel one or more echoes caused by an electricalmismatch between transmission media in one or more portions of thenetwork. Echo processing may introduce distortion to the referencespeech sample transmitted through the communication system. Echocancellers utilizing the G.165 and G.168 standards may be employed, forexample.

Subsequently, the reference speech sample is transmitted to an exemplaryvoice activity detector (VAD) 320. To more efficiently use bandwidth, avoice activity detector (or VAD) 320 is used to suppress thepacketization of voice signals between individual speech utterances(i.e. during the silent periods) within a voice conversation. The VAD320 generally operates on the transmit side of a gateway, and may beconfigured to trigger when reaching a particular threshold. If the VAD320 is not operating correctly it may reduce the voice quality of areference speech sample. Excessive front end clipping (FEC), forexample, may cause distortion in the reference speech sample signal.Excessive hold-over time (HOT) reduces bandwidth efficiency, while shorthold-over times may produce choppy speech utterances. Such effects, whenrealized, may cause a degradation in the voice quality of the referencespeech sample transmitted through the communication system under test.

Thereafter, the reference speech sample is transmitted to an exemplaryfirst codec 316 where the reference speech sample is digitized andcompressed according to one or more compression standards. Again, thefirst codec may be implemented in the previously described VoIP gateway.The first codec 316 may process the reference speech sample using thefollowing exemplary ITU G.7XX standards: G.711, G.722, G.723, G.726,G.729. The first codec 316 acts as an encoder to encode the referencespeech sample using one of these standards. In performing itsprocessing, the first codec 316 may introduce varying levels of voicequality degradation. The degradation may be associated with the type ofcompression used. It is contemplated that the first codec 316 isinactive when the VAD 320 is triggered.

Thereafter, the reference speech sample is transmitted to an exemplarypacketizer 324 that packages the payload and applies an appropriateheader and trailer prior to transmitting the reference speech sample toa wide area network. The first codec may be implemented within thepreviously described VoIP gateway. It is contemplated that packetizationerrors may comprise one or more lost or reordered packets. One or moretypes of packets may be generated for transmission to an appropriatewide area network service by way of a first wide area network serviceinterface 328. In one exemplary embodiment, the reference speech sampleis packetized and transmitted by way of an appropriate protocol, such asan exemplary Real Time Protocol (RTP), suitable for voice transmission.The reference speech sample packets are further transmitted through awide area network (WAN) service 330 by way of an exemplary ATM, framerelay, or Internet based network infrastructure.

While traversing the WAN, the reference speech sample packets mayencounter a number of exemplary network switches and routers 332.Processing at a router or a switch may have an effect on speech quality.For example, any switching and/or routing delays may cause one or morereference speech sample packets to be discarded. A lost packet may havea significant effect on speech quality. In another example, the trafficcapacity of a network may exceed the handling capacity of one or morenetwork routers or switches, effectuating a loss of packets.

The reference speech sample may be transmitted over various transmissionmedia 336 while traversing the WAN. The transmission media 336 may havean effect on the voice quality of the reference speech sample. Forexample, if the transmission media 336 is damaged, the voice quality ofthe reference speech sample may be reduced. In another example, longtransmission distances of the transmission media 336 may cause signalattenuation resulting in distortion of the transmitted reference speechsample corresponding to reduced voice quality and a lowered voicequality score. After traversing the WAN, the reference speech signalexits the WAN by way of a second WAN service interface 338.

A network interface 340 is illustrated on the transmit side of the voicecommunication system under test. The network interface 340 provides acommunication interface between the exemplary processing elementspreviously described (i.e., ECAN 312, codec 316, VAD 320, and packetizer324) and the voice analysis platform 304. The network interface 340 maybe attached to the computing device that implements the voice over IPgateway. The ECAN 312, codec 316, VAD 320, and packetizer 324 mayprovide outputs, as shown, that are transmitted back to the voiceanalysis platform 304. The voice analysis platform 304 may subsequentlygenerate one or more voice quality scores by comparing one or more ofthese outputs, containing the captured reference speech sample, to theoriginally transmitted reference speech sample.

After exiting the WAN, the reference speech sample packets are receivedby a jitter buffer 344 that acts to smooth out delay variances in thereceived reference speech sample. Inadequate jitter buffer size maysignificantly affect the voice quality of the reference speech sample.In certain cases, packets may be dropped, resulting in significant dropsin voice quality. In other instances, the time characteristics of thereference speech sample may be altered.

Thereafter, the reference speech sample is transmitted to an exemplaryreceive side second codec 352 complementary to that of the transmit sidefirst codec 316 described earlier. Again, the second codec 352 may beimplemented within the previously described VoIP gateway. The secondcodec 352 decodes the signal that was previously encoded by the firstcodec 316. The signal is decoded using the same standard used to encodethe signal by the first codec 316. In processing the received referencespeech sample, the second codec 352 may introduce varying levels ofvoice quality degradation. The degradation may be associated with thetype of compression algorithm used.

Complementary to the transmit-side VAD 320 previously described, anexemplary Comfort Noise Generator (CNG) 348 generates a local comfortnoise signal to the listener during silent periods. If the CNG 348functions abnormally, noise may be generated during periods of speechtransmission, causing distortion of the reference speech sampletransmitted. This may result in a reduction of speech quality.

The reference speech sample is further transmitted to an exemplarysecond echo canceller (ECAN) 356 from the second codec 352. The secondecho canceller 356 may be implemented within an exemplary computingdevice that functions as a voice over IP gateway. The echo cancellers312, 356 may utilize ITU G.165 and G.168 standards, for example.

Thereafter, the reference speech sample is transmitted to the secondPSTN 360. The reference speech sample may be affected by an exemplarybackground noise that is added to the reference speech sample. It iscontemplated that other forms of voice quality degradation may occur atthe second PSTN 360. Such voice quality degradation may occur by way ofsignal loss, cross talk, and the like.

The reference speech sample is received by the second voice analysisplatform 368 from the second PSTN 360. The second voice analysisplatform 368 analyzes the received reference speech sample andcalculates a voice quality score. The voice quality score may bedisplayed by way of a graphical display provided by an exemplarymonitor.

A second network interface 364 is illustrated on the receive side of thevoice communication system under test. The network interface 364provides a communication interface between the exemplary VoIP gatewayprocessing elements and the voice analysis platform 304. The receiveside voice over IP gateway may facilitate transmitting one or moreoutputs from the second ECAN 356, second codec 352, CNG 348, and jitterbuffer 344, as shown in FIG. 3, back to the second voice analysisplatform 368, where a voice quality score may be generated. Further, theoutput of the second WAN service interface 338 may be ported through thesecond network interface 364 to the second voice analysis platform 368.The voice analysis platform 368 may subsequently generate one or morevoice quality scores based on the one or more reference speech sampleoutput(s) it receives from the voice communication system under test.

The embodiment illustrated in FIG. 3 depicts a communication systemwhose endpoints are not co-located. It is further contemplated that aconfiguration similar to that provided by the embodiment of Figure 1bmay be implemented when the endpoints of the voice communication systemare co-located. As discussed previously, the embodiment comprises asingle voice analysis platform connected to a voice communication systemunder test. This type of configuration may be used in a laboratoryenvironment.

FIG. 4 a is an operational flow diagram illustrating an exemplary methodof assessing voice quality of service in accordance with an embodimentof the invention. At step 404, a user determines a point in the voicecommunication system where a transmitted reference speech sample will betapped. At step 408, the user may input instructions by way of the userinterface of the voice analysis platform, thereby specifying an outputof a signal processing element that is to be tapped. The voice analysisplatform subsequently transmits the instructions to the appropriatevoice over IP gateway or other device of the communication system. Inone embodiment, network processing elements such as routers and/orswitches may be configured to provide such outputs when loaded withenabling software compatible to that of the software resident in thevoice analysis platform. At step 412, the voice analysis platformtransmits a reference speech sample designated by the user. At step 416,the voice analysis platform receives the reference speech sample from apoint in the voice communication system under test. The reference speechsample may be transmitted from a particular processing element (in aparticular voice over IP gateway), for example, by way of controlestablished through use of a remote version of the voice analysisplatform software installed at the voice over IP gateway. The referencevoice sample may be appropriately filtered and captured by the voiceover IP gateway. The captured reference speech sample may be transmittedto the voice analysis platform by way of any network such as a packetswitched network. At step 420, the voice analysis platform processes thereceived reference speech sample output. At step 424, the voice analysisplatform displays voice quality scores generated by a specifiedalgorithm. The score may be displayed graphically over time and mayinclude an average voice quality score over the duration of thereference speech sample. Proceeding to FIG. 4 b, at step 428, the usermay wish to generate another voice quality score from another pointalong the transmission path of the communication system. If the userwishes to generate another score from another point, the process revertsback to step 404, wherein the user determines a point in the voicecommunication system where a reference speech sample will be outputfrom. If the user does not wish to generate an additional voice qualityscore at another point, the process proceeds to step 432. At step 432,the results of the processing performed by the voice analysis platformmay be analyzed by the user. At step 436, the user may determine basedon the voice quality scores provided, that one or more processingelements may require improvement. At step 440, one or more processingelements may be modified or replaced. And at step 444, the user mayre-obtain voice quality scores at the same points to verify that voicequality has been improved after the modifications or replacements havebeen made.

FIG. 5 is an exemplary display provided to a user of a voice analysisplatform illustrating exemplary voice quality scores 500 that aredisplayed in accordance with an embodiment of the invention. It iscontemplated that an exemplary computer monitor may be used to providethe display. As illustrated, the voice quality scores are displayed nextto their corresponding processing element outputs. In this embodiment,the voice quality scores vary from 0 (poor voice quality) to 5(excellent voice quality). As shown, the reference speech sample has avoice quality score of 5.0 prior to being transmitted to thecommunication system. As the reference speech sample is transmittedthrough the communication system, the voice quality scores are reduced,signifying degradation in the voice quality. In the embodiment shown,the voice quality score at the receiving end of the voice qualityplatform is 2.70. By displaying the voice quality scores graphically, auser may easily notice significant variations in voice quality scoresover time. In one embodiment, one or more average voice quality scorescalculated over the duration of the reference speech sample aredisplayed adjacent to the appropriate signal processing outputs of thecommunication system.

While the invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the invention without departing from its scope.Therefore, it is intended that the invention not be limited to theparticular embodiment disclosed, but that the invention will include allembodiments falling within the scope of the appended claims.

1. An apparatus for generating a voice quality score within acommunication system comprising a voice analysis platform that generatesa reference speech sample for transmission into said communicationsystem, said voice analysis platform provides configuration data toinstruct at least one signal processing device to provide at least oneoutput of said reference speech sample at a signal processing pointwithin said at least one signal processing device, and said voiceanalysis platform generates at least one voice quality score based onsaid at least one output.
 2. The apparatus of claim 1 further comprisinga display to provide a graphical diagram of said communication systemindicating said at least one voice quality score.
 3. The apparatus ofclaim 2 wherein said graphical diagram graphically associates said atleast one voice quality score with said at least one output.
 4. Theapparatus of claim 1 comprising at least one communication software,wherein said at least one communication software comprises a serverversion of said communication software.
 5. The apparatus of claim 1comprising at least one communication software, wherein said at leastone communication software comprises a client version of saidcommunication software.
 6. The apparatus of claim 1 wherein said voiceanalysis platform is configured to transmit and receive said at leastone reference speech sample.
 7. The apparatus of claim 1 wherein said atleast one signal processing device comprises a voice over IP gateway. 8.The apparatus of claim 1 wherein said at least one signal processingdevice stores and executes a software capable of communicating saidconfiguration data with at least one communication software of saidvoice analysis platform.
 9. An apparatus for generating a voice qualityscore within a communication system comprising at least a first voiceanalysis platform configured to transmit said at least one referencespeech sample and at least a second voice analysis platform configuredto receive said at least one reference speech sample.
 10. An apparatusfor generating a voice quality score within a communication systemcomprising: at least a first voice analysis platform capable ofgenerating and transmitting a reference speech sample; and at least asecond voice analysis platform capable of receiving said referencespeech sample, wherein said at least first voice analysis platform orsaid at least second voice analysis platform analyzes at least oneoutput of said reference speech sample provided at a signal processingpoint within a signal processing device of said communication system.11. A method of assessing voice quality of a communication systemcomprising: transmitting reference speech samples into saidcommunication system; receiving said reference speech samples capturedat one or more outputs of a signal processing element of a gatewaywithin said communication system; and determining voice quality scoresbased on said captured reference speech samples.
 12. The method of claim11 further comprising displaying said voice quality scores graphically.13. The method of claim 12 wherein said displaying occurs by way of agraphical user interface.
 14. The method of claim 11 further comprisingdetermining said one or more outputs of a signal processing element of agateway within said communication system in which to capture saidreference speech samples.
 15. The method of claim 11 further comprisingdetermining and displaying statistical information related to said voicequality scores.
 16. The method of claim 15 wherein said statisticalinformation comprises an average voice quality score and a variance. 17.The method of claim 11, wherein said gateway comprises a voice over IPgateway.
 18. A method of generating voice quality scores of acommunication system comprising: transmitting a reference speech sampleinto said communication system; and receiving said reference speechsample captured as an output of a signal processing element of a signalprocessing device within said communication system.